Open-hearth furnace and apparatus for charging the same



May 24, 1932. v w SUNDBLAD 1,859,754

OPEN HEARTH FURNACE AND APPARATUS FOR CHARGING THE SAME Fi led Aug. 1, 1950 5 Sheets-Sheet 1 [N VENTOR f'd/A'e 14 Sana/15km.

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y 1932- F. W.SUYNDBLAD 1,859,754

OPEN HEARTH FURNACE AND APPARATUS FOR CHARGING THE SAME Filed Aug. 1, 1930 5 Sheets-$heet 2 WwM/L A TTORNE Y.

y 24, 1932- F. w. SUNDBLAD W 1,859,754

OPEN HEABTH FURNACE AND APPARATUS FOR CHARGING THE SAME Filed Aug. 1, 1930 3 ShGGtS-ShGGL 5 INVENTOR. wzb j f/k? 14/ 6U/7db/ad.

ATTORNEY.

Patented May 24, 1932 FOLKE W. SUNDIBLAD, OF STEU BENVILLE, OHIO OPEN-HEARTH FURNACE AND QIPARATUS FOR CHARGING THE SAME Application filed August 1;

This invention relates to a new and improved open-hearth furnace and to a method and apparatus for charging the same, and more particularly an open-hearth furnace of l!- thetilting type.

The present methods of charging openhearth furnaces were developed at a time when charges, aside from hot metaLconsisted almost entirely of metal in relatively heavy T07 masses, for example, blooms, billets and so called heavy scrap, and have proved inade-' quate for charging light scrap, such, for example, as that obtained from the automobile industry and known as automobile scrap. When it is attempted to charge light scrap of this character into an open-hearth furnace according to methods now generally in use, the lightness and bulk of the scrap require charging operations of such complexity and W duration as to more than offset the advantages due to the cheapness and availability of this light scrap.

VVhen it is realized that about of all the steel produced in this country goesinto the automotive industry and the average period of circulation of metal in the automotive industry is only about five or six years, it will be evident that the desirability of a rapid and effective method of charging light scrap of this character is very great.

An object of the present invention is toprovide an open-hearth furnace which may be charged with lightand bulky scrap in a rapid and eflicacious manner, and a method of and apparatus for so charging the furnace.

My invention has for further objects such other operative advantages or results as may hereinafter be found to obtain.

According to my invention, I provide an open-hearth furnace of the so-called tilting type but having a charging door so disposed as to permit charging the furnace with heavy scrap in the usual mannerthat is, while in the normal or horizontal position,but nev-- ertheless so disposed as to permit charging the furnace from above and by gravity while in a tilted position.

I accomplish this in part by providing a charging door located at such an angle with the vertical as to permit charging in the usual .1930. a Serial No. 472,252.

manner while the furnace is in the horizontal position but nevertheless at such an angle as to permit bringing the charging door into a substantially horizontal position by tilting the furnace within a permissible degree of rotation. V

For eXampleI may provide a charging inlet and door located in a plane at anangle of about 35 from the vertical so that by tilting the furnace through an angle of rotation of about from its horizontal position the charging door may be brought into a substantially horizontal plane, in which position light scrap may be charged by gravity from above.

' Vhile the above figures represent the preferred angle of the door and inlet and the preferred angle ofrotation of the furnace, they may be varied somewhat in individual instances. For example, the angle of the charging door and inlet may vary from about 30 to 45 from the vertical, and the angle of rotation from '60' to 45, the sum of the two angles in each instance being about 90.

My invention also contemplates various improvements in details of construction of the furnace and charging mechanism and in the method of charging the furnace, as will be apparent from the description given herein below .and the claims hereinafter made In order that my invention may be clearly setforth and understood I now describe with reference to the accompanying drawings, a preferred form and manner in which my invention may be embodied and accomplished. In these drawings 7 Figure 1 is a view, partly in elevation and partly in vertical section, of an open-hearth furnace constructed in accordance with my invention, taken from a positionin front of the charging doors of the furnace;

Fig. 2 is a plan view of a portion of the apparatus shown in Fig. 1; V Figs. 3 and 4 are elevational and vertical sectional views, respectively, of a portion of the apparatus shown in Figs. 1 and 2, including especially a charging door and inlet thereof, Fig. 4 being taken along the line IV-IV of Fig. 3; and

Fig. 5 is a vertical sectional view of a typical installation of the furnace shown in the preceding figures, including also additional details of auxiliary charging mechanism.

Similar characters of reference designate similar parts in each of the several views of the drawings.

Referring to the drawings, the open-hearth furnace 1 is in many respects similar to the standard tilting furnace of the prior art, being lined with refractory material, mounted on trunnions 2 mounted on blocks 2a, and provided with the usual fuel regenerators 3 and passages 4 and 5 located in stationary flue structures 6 at each end of the furnace 1 for introduction of air and gas into the interior thereof and withdrawal of products of combustion therefrom in the usual manner.

In the preferred instance, the center line of the furnace 1 is located as a continuation of the center line of the gas and air ducts in the structures 6 at the junctions with the furnace 1, so that tilting the furnace does not necessarily interrupt the introduction of fuel or Withdrawal of products of combustion or expose the ducts 4 or 5 to the atmosphere.

It may be noted at this point that while the trunnions 2 and other tilting mechanism, further details of which are too well known to require description, are in general similar to those which have been proposed and used for tilting open-hearth furnaces in the past, they are nevertheless so constructed (as will be apparent from the description given below) as to permit a somewhat larger angle of rotation of the furnace than has been common in the prior art.

The furnace 1 is provided with the usual accessories, including an emptying spout 8, or a plurality thereof, located in the usual position.

The details of a preferred form of charging door are illustrated in Figs. 3 and 4. It will be noted from these figures that the roof arch 9 and the fore-wall arch 10 of the furnace 1 meet at a point just above a charging opening 11 of the furnace 1. At this point there is provided an angle 13, and preferably also an adjacent cooling-water passage 14, the angle 13 being so located (as will be obvious from Fig. 4) as to support not only the roof arch 9 but also the fore-wall arch 10. By reason of this fact any impairment of the fore-wall arch which may take place during the tilting operation will not affect the roof arch, and vice versa.

Adjacent to and outside the charging opening 11 there is located a water cooling frame 15 having an opening 16 corresponding to the opening in the fore-wall, and provided with a charging door 17. In the preferred instance illustrated the charging door 17 is lo,- cated in a plane at an angle of approximately 35 with the verticalv and in any event is so located as to permit charging in the usual manner from the floor in front of the furnace while the furnace is in a horizontal po-- sition when desired. The doors 17 are con-- veniently operated by means of cables 18 and motors 19 or by any other suitable means.

There may be any suitable number of charging openings 11 and corresponding doors 17, according to the size of the furnace 1, although in the instance illustrated in the drawings three are provided. In most instances however, the charging of light scrap will be confined to the more central portions of the furnace 1, and end doors 17 a for charging in the usual manner only may be provided which are similar to those now in use.

By means of suitable motive mechanism (not shown) the furnace 1 may be tilted upon the trunnions 2 to an angle of approximately from the horizontal or in any event to such an angle that the charging doors 17 are brought into a horizontal or nearly horizontal plane, in which position the furnace is shown in Fig. 5.

Immediately above the position of the charging doors 17 and openings 11, while in this extreme tilted position of the furnace 1 there are located suitable devices for dis charging scrap or other material into the furnace by gravity. In the present instance this consists of chutes 20 supplied with material from conveyors 21 and chutes 22 and discharging against deflectors 23, or directly, into the charging openings 11 of the furnace 1.

When it is desired to charge the furnace with light scrap or the like, a car 25 containing the same, for example a standard railway car, is elevated to an upper floor 26 of the building in which the furnace 1 is located and the scrap is withdrawn from the car 25 by means of an electro-magnet 27 suspended from a crane 28 and transferred to the convcyors 21 which carry it to the chutes 22 and 20 by means of which it is delivered through the charging opening 11 of the furnace 1, the latter being at the time of charging in the tilted position.

After this charging operation is completed, the furnace may be rotated back to the normal position for the melting and processing operations.

During periods of charging, the furnace may be prevented from cooling off by the introduction of small quantities of gas and air or by means of a tar or oil flame from one of a plurality of burners 30 suitably located.

When it is desired to charge the furnace 1 with heavy scrap or the like the furnace 1 may be held in the normal or horizontal position and charged by means of charging buggies 31 and a charging device 32 in the usual manner through the doors 1'? and 17 a, or through the'latter only. As in most instances both heavy and light masses of metal will be charged into the furnace, the buggies 31 and charging device 32 will not ordinarily be dispensed with. Hot metal may also be charged from ladles in the usual manner.

The other operations entering into the handling of the furnace, such as the discharging operation of the processing of the metal which takes place in the furnace, donot differ in any way from the same operations when conducted in a similar type of furnace and need not be discussed in further detail. It may be noted, however, that the charging period may be followed by a relatively short reheating period.

According to my invention it is possible to charge an open-hearth furnace, even one of extremely large size, for example 350 tons capacity, largely or even entirely with light scrap in a very short time, for example three hours; whereas, in prior types of furnaces the same charging operation might easily require as much as fifteen hours. For this reason, relatively cheap scrap and waste products of the automobile industry may be used for the making of steel without difficulty and the production cost of the finished metal will be greatly reduced.

Furthermore, the labor and other charges which have been incident to the handling of light scrap in the past (when such scrap was charged at all) are largely eliminated by my invention. For example, it formerly required, or would have required, a large force of men for the maintenance crew of the scrap yard, the arrangement and classification of various sorts of material, and the arrangement of the material upon the charging buggles.

It will therefore be apparent that according to my invention the labor requirements may be reduced and furnaces of larger capacities than have been practicable heretofore can be constructed and operated without difliculty. In addition to these advantages, the well known advantages of the tilting type of open hearth furnace may be realized, and

other advantages will instantly suggest themselves to those skilled in the art.

To those skilled in the art it will moreover be obvious that my invention is not limited to the specific instance or instances. given hereinabove by way of illustrative example, but may be variously practiced and embodied within the scope of the claims hereinafter made.

I claim: v

1. An open-hearth steel furnace, means for tilting the same from a horizontal operating positionthrough an arc of not more than sixty degrees to a charging position, and a charging door located in the side of said furnace at such an angle with the horizontal when the furnace is in its operating position that it will assume a substantially horizontal position above the furnace when the same is tilted into its charging position. i

2. An open-hearth furnace of the tilting type, having a charging opening lying in a plane at an angle of from 30 to 45 from the vertical While said furnace is in its normal or horizontal position, and adapted to be tilted through an angle of from 60 to 4L5, whereby said charging opening is brought into a substantially horizontal position.

3. An open-hearth furnace of the tilting type, having a charging opening lying in a plane at an angle of substantially 35 from the vertical while said furnace is in its normal or horizontal position, and adapted to be tilted through an angle of substantially 55, whereby said charging opening is brought into a substantially horizontal position.

4. In combination an open-hearth furnace located within a housing structure, a charging door in one side of said furnace, a charging floor for heavy metal located in front of the furnace, and carrying means for charging said furnace laterally and a second floor located above said charging floor and charging means and carrying means for conveying light metal to a point adjacent to said charging door.

5. In combination an open-hearth furnace located within a housing structure, a charging door in one side of said furnace, a charging floor for heavy metal located in front of the furnace, and carrying means for charging said furnace laterally and a second floor located above said charging floor and charging means and carrying means for conveying light metal to a point above said furnace, said furnace being adapted to be tilted through an are sufficient to move said charging door from a position in front of said charging means to a position adjacent to said conveying means and vice versa.

In testimony whereof, I have hereunto subscribed my name this 26th day of July, 1930.

FOLKE W. SUNDBLAD. 

